Homemark gift card

I received a Homemark gift voucher end of August and have been calling to activate it for 3 weeks now, they do take my details and the card number tell me to wait for an SMS that will be sent within 48hours after 48 hours I call and ask why haven't I received the SMS they say my card was not activated and they will call me back. What must I rally do to activate this card cause today they are not answering my calls?